Barrie Margetts

Weight in infancy and death from ischaemic heart disease.

Environmental influences that impair growth and development in early life may be risk factors for ischaemic heart disease. To test this hypothesis, 5654 men born during 1911-30 were traced. They were born in six districts of Hertfordshire, England, and their weights in infancy were recorded. 92.4% were breast fed. Men with the lowest weights at birth and at one year had the highest death rates from ischaemic heart disease. The standardised mortality ratios fell from 111 in men who weighed 18 pounds (8.2 kg) or less at one year to 42 in those who weighed 27 pounds (12.3 kg) or more. Measures that promote prenatal and postnatal growth may reduce deaths from ischaemic heart disease. Promotion of postnatal growth may be especially important in boys who weigh below 7.5 pounds (3.4 kg) at birth.

Deprivation, diet, and food-retail access: findings from the Leeds 'food deserts' study

Within a context of public policy debate in the United Kingdom on social exclusion, health inequalities, and food poverty, the metaphor of the ‘food desert’ caught the imagination of those involved in policy development. Drawing from a major cross-disciplinary investigation of food access and food poverty in British cities, the authors report in this paper findings from the first ‘before/after’ study of food consumption in a highly deprived area of a British city experiencing a sudden and significant change in its food-retail access. The study has been viewed as the first opportunity in the United Kingdom to assess the impact of a non-healthcare intervention (specifically a retail-provision intervention) on food-consumption patterns, and by extension diet-related health, in such a deprived, previously poor-retail-access community. The paper offers evidence of a positive but modest impact of the retail intervention on diet, and the authors discuss the ways in which their findings are potentially significant in the context of policy debate.

Dietary calcium, physical activity, and risk of hip fracture: a prospective study.

OBJECTIVE--To determine whether low dietary calcium intake and physical inactivity are risk factors for hip fracture among subjects aged 65 and over. DESIGN--Fifteen year follow up study of a large cohort of randomly selected elderly people living in the community, who had taken part in the 1973-4 survey of the Department of Health and Social Security, and for whom dietary and other data were recorded at initial interview and medical assessment. SETTING--Eight areas in Britain (England (five), Wales (one), and Scotland (two]. SUBJECTS--1688 Subjects living in the community, of whom 1419 subjects (720 men and 699 women) agreed to participate. 1356 Subjects completed a seven day dietary record and 983 (542 men and 441 women) agreed to be assessed by a geriatrician. RESULTS--Incidence of hip fracture increased with age and was higher in women than men. Comparison with matched controls showed no evidence that the risk of hip fracture was related to calcium intake: the odds ratio for the lowest third of dietary calcium compared with the highest was 0.7 (95% confidence interval 0.1 to 3.9) after adjustment for smoking and body mass index. The adjusted odds ratio for the lowest third of outdoor activity compared with the highest was 4.3 (0.7 to 26.8), and that for grip strength was 3.9 (0.7 to 23.0). CONCLUSIONS--Reduced intake of dietary calcium does not seem to be a risk factor for hip fracture. Further evidence is provided that physical activity in the elderly protects against hip fracture.

Food-frequency questionnaires: a review of their design, validation and utilisation

A review of the literature concerning the design, utilisation and validation of food-frequency questionnaires (FFQ) has been carried out using a semi-systematic approach to obtaining, reviewing and extracting data from articles. Databases were searched from 1980 to 1999. The present review identified 227 validation (from 1980 to September 1999) and 164 utilisation (for 1998 only) studies. A number of design issues have been evaluated through the present review. These include: the need to consider how portion sizes have been described, self-defined giving higher mean correlations; how an FFQ was administered, interviewer-administered giving higher mean correlations for some nutrients; how many items to include on an FFQ, those with the largest number of items having higher correlations. Validation techniques were described. Most validation studies involved comparing an FFQ against another dietary assessment method; only 19 % compared an FFQ to a biomarker. Measurement differences were most commonly assessed by correlation coefficients as opposed to other more appropriate methods. Mean correlation coefficients were highest for Ca and fat, and lowest for vitamin A and vegetables. The utilisation studies showed that FFQ were most commonly used in cross-sectional surveys, with ninety-three of the FFQ being designed to be disease-specific. The present review results were presented to a group of experts and a consensus arrived at concerning the development, validation and use of FFQ. Recommendations derived from the consensus arising from the literature review are presented as an appendix to the present paper.

Vegetarian diet in mild hypertension: a randomised controlled trial.

In a randomised crossover trial 58 subjects aged 30-64 with mild untreated hypertension were allocated either to a control group eating a typical omnivorous diet or to one of two groups eating an ovolactovegetarian diet for one of two six week periods. A fall in systolic blood pressure of the order of 5 mm Hg occurred during the vegetarian diet periods, with a corresponding rise on resuming a meat diet. The main nutrient changes with the vegetarian diet included an increase in the ratio of polyunsaturated to saturated fats and intake of fibre, calcium, and magnesium and a decrease in the intake of protein and vitamin B12. There were no consistent changes in urinary sodium or potassium excretion or body weight. In untreated subjects with mild hypertension, changing to a vegetarian diet may bring about a worthwhile fall in systolic blood pressure.

Physical inactivity is the major determinant of obesity in black women in the North West province, South Africa: the THUSA study

OBJECTIVE We investigated the association between measures and determinants of obesity in African women. METHODS For a cross-sectional study of adult black women in the North West Province, South Africa, we used a stratified sample of 1040 volunteers from 37 randomly selected sites in the province according to the level of urbanization. We analyzed the association between measures of obesity, namely body mass index (BMI), waist circumference, waist-to-hip ratio, triceps and subscapular skinfolds, and socioeconomic factors, dietary intakes, and physical activity. RESULTS The rate of obesity (BMI > 30) in the sample was 28.6%. We found a significant positive association between household income and measures of obesity. After exclusion of underreporters and adjustments for age, smoking, and household income, we found significant positive correlations between total energy intake, fat intake, and BMI. Physical activity index (derived from a subset of 530 subjects) correlated negatively with BMI and waist circumference. Subjects in the highest third of physical activity were less likely to be obese (odds ratio-0.38, 95% confidence interval-0.22-0.66). CONCLUSIONS Women with higher incomes and lower physical activity were at the greatest risk of increased BMI. Physical inactivity showed the strongest association with measures of obesity in this study.

Prevalence of risk of undernutrition is associated with poor health status in older people in the UK

Objective: To establish the prevalence of the risk of undernutrition, using criteria similar to those used by the Malnutrition Advisory Group (MAG), in people aged 65 y and over, and to identify relationships between risk of undernutrition and health and demographic characteristics.Design: A cross-sectional nationally representative sample of free-living and institutionalized older people in the UK (65 y of age and over). Secondary analysis of the National Diet and Nutrition Survey based on 1368 people aged 65 y and over.Results: About 14% (21% in those living in institutions) were at medium or high risk of undernutrition based on a composite measure of low body mass index and recent reported weight loss. Having a long-standing illness was associated with a statistically significantly increased risk of undernutrition (odds ratio: men 2.34, 95% CI 1.20–4.58; women 2.98; 1.58–5.62). The risk of undernutrition increased: in women reporting bad or very bad health status; in men living in northern England and Scotland; for those aged 85 y and older; for those hospitalized in the last year, and those living in an institution. Lower consumption of energy, meat products or fruit and vegetables and lower blood measures of zinc, vitamins A, D, E and C were associated with statistically significantly increased risk of undernutrition.Conclusion: A substantial proportion of the older population of the UK is at risk of undernutrition. High-risk subjects are more likely to have poorer health status. It is unlikely that the individuals at high risk are being detected currently, and therefore effective care is not being provided, either in the community or in institutions.Sponsorship: This analysis was partly funded by a grant from the Department of Health. We are grateful for helpful comments from Professor MJ Wiseman and the anonymous reviewers.

Multiple micronutrient supplementation during pregnancy in low-income countries: A meta-analysis of effects on birth size and length of gestation

Background Multiple micronutrient deficiencies are common among women in low-income countries and may adversely affect pregnancy outcomes. Objective This meta-analysis reports the effects on newborn size and duration of gestation of multiple micronutrient supplementation mainly compared with iron plus folic acid during pregnancy in recent randomized, controlled trials. Methods Original data from 12 randomized, controlled trials in Bangladesh, Burkina Faso, China, GuineaBissau, Indonesia, Mexico, Nepal, Niger, Pakistan, and Zimbabwe, all providing approximately 1 recommended dietary allowance (RDA) of multiple micronutrients to presumed HIV-negative women, were included. Outcomes included birthweight, other birth measurements, gestation, and incidence of low birthweight (LBW) (< 2,500 g), small-for-gestational age birth (SGA, birthweight below the within-each-population 10th percentile), large-for-gestational age birth (LGA, birthweight above the within-each-population 90th percentile), and preterm delivery (< 37 weeks). Results Compared with control supplementation (mainly with iron–folic acid), multiple micronutrient supplementation was associated with an increase in mean birthweight (pooled estimate: +22.4 g [95% CI, 8.3 to 36.4 g]; p = .002), a reduction in the prevalence of LBW (pooled OR = 0.89 [95% CI, 0.81 to 0.97]; p = .01) and SGA birth (pooled OR = 0.90 [95% CI, 0.82 to 0.99]; p = .03), and an increase in the prevalence of LGA birth (pooled OR = 1.13 [95% CI, 1.00 to 1.28]; p = .04). In most studies, the effects on birthweight were greater in mothers with higher body mass index (BMI). In the pooled analysis, the positive effect of multiple micronutrients on birthweight increased by 7.6 g (95% CI, 1.9 to 13.3 g) per unit increase in maternal BMI (p for interaction = .009). The intervention effect relative to the control group was + 39.0 g (95% CI, +22.0 to +56.1 g) in mothers with BMI of 20 kg/m 2 or higher compared with −6.0 g (95% CI, −8.8 to +16.8 g) in mothers with BMI under 20 kg/m2. There were no significant effects of multiple micronutrient supplementation on birth length or head circumference nor on the duration of gestation (pooled effect: +0.17 day [95% CI, −0.35 to +0.70 day]; p = .51) or the incidence of preterm birth (pooled OR = 1.00 [95% CI, 0.93 to 1.09]; p = .92). Conclusions Compared with iron–folic acid supplementation alone, maternal supplementation with multiple micronutrients during pregnancy in low-income countries resulted in a small increase in birthweight and a reduction in the prevalence of LBW of about 10%. The effect was greater among women with higher BMI.

The nutrition and health transition in the North West Province of South Africa: a review of the THUSA (Transition and Health during Urbanisation of South Africans) study.

OBJECTIVE To describe how urbanisation influences the nutrition and health transition in South Africa by using data from the THUSA (Transition and Health during Urbanisation of South Africans) study. DESIGN The THUSA study was a cross-sectional, comparative, population-based survey. SETTING The North West Province of South Africa. SUBJECTS In total, 1854 apparently healthy volunteers, men and women aged 15 years and older, from 37 randomly selected sites. Pregnant and lactating women, those with diagnosed chronic diseases and taking medication, with acute infections or inebriated were excluded but screened for hypertension and diabetes mellitus. Subjects were stratified into five groups representing different levels of urbanisation in rural and urban areas: namely, deep rural, farms, squatter camps, townships and towns/cities. OUTCOME MEASURES AND METHODS: Socio-economic and education profiles, dietary patterns, nutrient intakes, anthropometric and biochemical nutrition status, physical and mental health indicators, and risk factors for non-communicable diseases (NCDs) were measured using questionnaires developed or adapted and validated for this population, as well as appropriate, standardised methods for the biochemical analyses of biological samples. RESULTS Subjects from the rural groups had lower household incomes, less formal education, were shorter and had lower body mass indices than those in the urban groups. Urban subjects consumed less maize porridge but more fruits, vegetables, animal-derived foods and fats and oils than rural subjects. Comparing women from rural group 1 with the urban group 5, the following shifts in nutrient intakes were observed: % energy from carbohydrates, 67.4 to 57.3; from fats, 23.6 to 31.8; from protein, 11.4 to 13.4 (with an increase in animal protein from 22.2 to 42.6 g day(-1)); dietary fibre, 15.8 to 17.7 g day(-1); calcium, 348 to 512 mg day(-1); iron from 8.4 to 10.4 mg day(-1); vitamin A from 573 to 1246 mug retinol equivalents day(-1); and ascorbic acid from 30 to 83 mg day(-1). Serum total cholesterol, low-density lipoprotein cholesterol and plasma fibrinogen increased significantly across groups; systolic blood pressure >140 mmHg was observed in 10.4-34.8% of subjects in different groups and diabetes mellitus in 0.8-6.0% of subjects. Women in groups 1 to 5 had overweight plus obesity rates of 48, 53, 47, 61 and 61%, showing an increase with urbanisation. Subjects from group 2 (farm dwellers) showed the highest scores of psychopathology and the lowest scores of psychological well-being. The same subjects consistently showed the lowest nutrition status. CONCLUSIONS Urbanisation of Africans in the North West Province is accompanied by an improvement in micronutrient intakes and status, but also by increases in overweight, obesity and several risk factors for NCDs. It is recommended that intervention programmes to promote nutritional health should aim to improve micronutrient status further without leading to obesity. The role of psychological strengths in preventing the adverse effects of urbanisation on health needs to be examined in more detail.

The Nutrition Transition in Africa: Can It Be Steered into a More Positive Direction?

The objective of this narrative review is to examine the nutrition transition and its consequences when populations in Africa modernize as a result of socio-economic development, urbanization, and acculturation. The focus is on the changes in dietary patterns and nutrient intakes during the nutrition transition, the determinants and consequences of these changes as well as possible new approaches in public health nutrition policies, interventions and research needed to steer the nutrition transition into a more positive direction in Africa. The review indicates that non-communicable, nutrition-related diseases have emerged in sub-Saharan Africa at a faster rate and at a lower economic level than in industrialized countries, before the battle against under-nutrition has been won. There is a putative epigenetic link between under- and over-nutrition, explaining the double burden of nutrition-related diseases in Africa. It is concluded that it is possible to steer the nutrition transition into a more positive direction, provided that some basic principles in planning public health promotion strategies, policies and interventions are followed. It is suggested that sub-Saharan African countries join forces to study the nutrition transition and implemented interventions on epidemiological, clinical and molecular (genetic) level for better prevention of both under- and over-nutrition.